Tangential on-board injectors for gas turbine engines

ABSTRACT

A tangential on-board injector for a gas turbine engine is provided. The tangential on-board injector includes a body having an entrance and an exit, the body having a curved shape and defining an air passageway between the entrance and the exit and an inlet extension connected to the entrance of the body, the inlet extension extending from the body and having an inlet configured to force air to change direction when entering the inlet of the inlet extension.

BACKGROUND

The subject matter disclosed herein generally relates to gas turbineengines and, more particularly, to tangential on-board injectors(“TOBI”).

Gas turbine engines may have particle accumulation therein, e.g., sand,dust, etc. The accumulation of such particles may lead to durabilitydistress due and/or other impacts may result. One result of particleaccumulation may be holes within the engine may plug or clog due to abuild-up of particles within the hole.

Small particles may not get rejected in the fan and compressor stages ofthe engine, and thus may be present in the secondary flow system of theengine. One point of particle accumulation may be proximal and/or in thetangential on-board injector (“TOBI”). Particles in the lower part ofthe engine may fall and/or collect near the TOBI due to gravity, and maycollect near the TOBI entrance. Further, any particles that enter theTOBI may be fed and supplied to the blade and feed the forward leak withthe particle-rich air. Thus, it may be advantageous to design a TOBIhaving an ability to prevent particles from being supplied therethrough.

SUMMARY

According to one embodiment, a tangential on-board injector for a gasturbine engine is provided. The tangential on-board injector includes abody having an entrance and an exit, the body having a curved shape anddefining an air passageway between the entrance and the exit and aninlet extension connected to the entrance of the body, the inletextension extending from the body and having an inlet configured toforce air to change direction when entering the inlet of the inletextension.

In addition to one or more of the features described above, or as analternative, further embodiments may include that the inlet extension isconfigured to direct air through an angle as the air flows through theinlet extension.

In addition to one or more of the features described above, or as analternative, further embodiments may include that the angle is equal toor greater than 90°.

In addition to one or more of the features described above, or as analternative, further embodiments may include that the inlet extension isintegrally formed with the body.

In addition to one or more of the features described above, or as analternative, further embodiments may include a purge cavity configuredalong the air passageway of the body, the purge cavity configured suchthat large particles in an airflow through the passageway will enter thepurge cavity.

In addition to one or more of the features described above, or as analternative, further embodiments may include that the purge cavity isconfigured to expel particles from the purge cavity to an annular cavityexternal to the body.

In addition to one or more of the features described above, or as analternative, further embodiments may include a separator located at theexit of the body, the separator configured to separate an airflowflowing through the air passageway into a first flow path and a secondflow path.

In addition to one or more of the features described above, or as analternative, further embodiments may include that the first flow path isdirected inboard relative to the body and the first flow path isdirected outboard relative to the body.

In addition to one or more of the features described above, or as analternative, further embodiments may include that each of the first flowpath and the second flow path are configured to direct air to coolcomponents of a gas turbine engine.

According to another embodiment, a method of manufacturing a gas turbineengine having a tangential on-board injector is provided. The methodincludes installing an inlet extension to an entrance of a body of thetangential on-board injector, the inlet extension extending from theentrance and having an inlet configured to force air to change directionwhen entering the inlet of the inlet extension.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include that theinlet extension is configured to direct air through an angle as the airflows through the inlet extension.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include that theangle is equal to or greater than 90°.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include that theinstallation comprises integrally forming the inlet extension with thebody of the tangential on-board injector.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include forming apurge cavity configured along the body, the purge cavity configured suchthat large particles in an airflow through the body will enter the purgecavity.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include configuringthe purge cavity to expel particles from the purge cavity to an annularcavity external to the body.

In addition to one or more of the features described above, or as analternative, further embodiments of the method may include forming aseparator at an exit of the body, the separator configured to separatean airflow flowing through the body into a first flow path and a secondflow path.

In another embodiment, a gas turbine engine is provided. The engineincludes a tangential on-board injector having a body having an entranceand an exit, the body having a curved shape and defining an airpassageway between the entrance and the exit and an inlet extensionconnected to the entrance of the body, the inlet extension extendingfrom the body and having an inlet configured to force air to changedirection when entering the inlet of the inlet extension.

In addition to one or more of the features described above, or as analternative, further embodiments of the engine may include that theinlet extension is configured to direct air through an angle as the airflows through the inlet extension.

In addition to one or more of the features described above, or as analternative, further embodiments of the engine may include a purgecavity configured along the air passageway of the body, the purge cavityconfigured such that large particles in an airflow through thepassageway will enter the purge cavity.

In addition to one or more of the features described above, or as analternative, further embodiments of the engine may include a separatorlocated at the exit of the body, the separator configured to separate anairflow flowing through the air passageway into a first flow path and asecond flow path.

Technical effects of embodiments of the present disclosure include animproved particle separation and air flow supply for a gas turbineengine. Further technical effects include an inlet extension configuredat an inlet to a TOBI of a gas turbine engine. Further technical effectsinclude a purge cavity within an air passage of a TOBI that isconfigured to enable purging particles from an airflow within the TOBI.Further technical effects include a separator configured at an outlet ofa TOBI that is configured to enable separation of airflows that exit theTOBI prior to being supplied to various components of a gas turbineengine for cooling. Further technical effects include providing separatecooling air supplies to airfoils of a gas turbine engine with varyingsizes of particles within the cooling air supplies.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be illustrative and explanatory in natureand non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter is particularly pointed out and distinctly claimed atthe conclusion of the specification. The foregoing and other features,and advantages of the present disclosure are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1A is a schematic illustration of a portion of a gas turbine enginehaving a tangential on-board injector (“TOBI”) that may employ one ormore embodiments described herein;

FIG. 1B is a baseline view of the TOBI of FIG. 1A;

FIG. 1C, shows a top-down view of two adjacent passageways of the TOBIof FIG. 1A;

FIG. 2A is a schematic illustration of a gas turbine engine inaccordance with a non-limiting embodiment;

FIG. 2B shows a top-down view of the TOBI along the line B-B of FIG. 2A;

FIG. 2C is a partial schematic view of an exit end of the TOBI of FIG.2A;

FIG. 3 is a schematic illustration of a gas turbine engine in accordancewith another non-limiting embodiment of the disclosure;

FIG. 4 is an alternative schematic view of a non-limiting example of apurge cavity configuration in accordance with an embodiment of thedisclosure;

FIG. 5A is an alternative schematic view of a non-limiting example of aninlet extension configuration in accordance with an embodiment of thedisclosure;

FIG. 5B is an alternative schematic view of a non-limiting example of aninlet extension configuration in accordance with an embodiment of thedisclosure;

FIG. 5C is an alternative schematic view of a non-limiting example of aninlet extension configuration in accordance with an embodiment of thedisclosure;

FIG. 6 is a process flow for manufacturing a gas turbine engine inaccordance with an embodiment of the disclosure; and

FIG. 7 is a process flow of operating a gas turbine engine in accordancewith an embodiment of the disclosure.

DETAILED DESCRIPTION

As shown and described herein, various features of the disclosure willbe presented. Various embodiments may have the same or similar featuresand thus the same or similar features may be labeled with the samereference numeral, but preceded by a different first number indicatingthe figure to which the feature is shown. Thus, for example, element “a”that is shown in FIG. X may be labeled “Xa” and a similar feature inFIG. Z may be labeled “Za.” Although similar reference numbers may beused in a generic sense, various embodiments will be described andvarious features may include changes, alterations, modifications, etc.as will be appreciated by those of skill in the art, whether explicitlydescribed or otherwise would be appreciated by those of skill in theart.

FIG. 1A is a schematic illustration of a portion of a gas turbine enginehaving a tangential on-board injector (“TOBI”). During operation, airdischarging from the TOBI is delivered into a cavity just ahead of theturbine. The cavity is typically sealed off by one or more seals thatinterface between the rotating and non-rotating structure of the gasturbine engine. Air may escape or pass through the one or more seals inthe form of leakage.

The arrows in FIG. 1A illustrate a cooling air flow discharging from theTOBI and distributed around and through a turbine portion of the gasturbine engine. As shown, a turbine 100 (partially shown) comprises adisk 102 supporting a plurality of circumferentially spaced blades 104(one being shown). A first seal 106 and a second seal 108 are configuredto define an annular cavity 110 just ahead of the turbine 100. A body112 of a TOBI defines an annular passageway 114 that is configured toreceive compressor discharge air and deliver it to the turbine rotorthrough a plurality of nozzles 116. The body 112 has an entrance 115 andan exit 117, with the nozzles 116 configured at the exit 117 of the body112.

FIG. 1B is a baseline view of the TOBI of FIG. 1A. As shown, a pluralityof entrances 115 may be formed in the body 112 of the TOBI. Althoughshown with entrances 115 covering 180° of the body 112 of the TOBI,those of skill in the art will appreciate that entrances 115 may coverthe full 360° of the body of the TOBI, or other configurations may beemployed. FIG. 1C, shows a top-down view of two adjacent passageways 114of the TOBI.

Sand, dust, and other particles may collect at each entrance 115 to theTOBI, such as at area 118 shown in FIG. 1A. The particles may thusinterfere with the operation of the gas turbine engine. For example,particles may settle at area 118 when the engine is shut down, and thenthe particles that settle or collect at area 118 may be sucked into theTOBI during a start-up operation.

Turning now to FIG. 2A, a schematic illustration of a gas turbine enginein accordance with a non-limiting embodiment is shown. In FIG. 2A, aturbine 200 (partially shown) comprises a disk 202 supporting aplurality of circumferentially spaced blades 204 (one being shown). Afirst seal 206 and a second seal 208 are configured to define an annularcavity 210 just ahead of the turbine 200. A body 212 of a TOBI defines apassageway 214 that is configured to receive compressor discharge airand deliver it to the turbine rotor through a plurality of nozzles. Thebody 212 has an entrance 215 and an exit 217 configured to allow air toflow through the passageway 214 of the TOBI.

As shown in FIG. 2A, the entrance 215 to the body 212 may include aninlet extension 220 having an inlet 222 attached thereto. The inletextension 220 may be attached by fasteners, welding, etc. to the body ormay be integrally formed with the body 212. The inlet extension 220 maybe configured, positioned, or angled such that air that flows from thecompressor must turn to enter the inlet extension 220 through the inlet222. As such, for example, when an engine is shut off, the particles maycollect in area 218 around a wall of the inlet extension 220, and uponstartup the particles may not be pulled into the passageway 214 of thebody 212. This is because the inlet extension 220 may provide a wall orother solid structure that will not allow the particles to passtherethrough. The inlet extension 220 is raised from the bottom of theinner case and angled or facing away from the flow.

Further, during operation, air will have to make a complete turn toenter the inlet 222. As such, large particles may not be able to remainwithin the air flow, and thus may fall to area 218 around a wall of theinlet extension 220 without entering the inlet 222. That is, the inletextension 220 may be configured to prevent particles from entering thepassageway 214 of the TOBI both during operation and when the engine isnot operational. In accordance with some non-limiting embodiments, theinlet extension 220 may be configured to filter out the largestparticles such that they do not enter the passageway 214 of the TOBI.

As shown in FIG. 2A, the body 212 of the TOBI may also include a purgemechanism 224. Purge mechanism 224 may be a cavity or channel, or otherconfiguration that is configured to allow particles to enter the purgemechanism 224 and have the particles then be purged therefrom. In FIG.2A, an arrow is shown extending upward from the body 212 through a purgeport 226. The purge port 226 may be a hole or aperture in a wall of thebody 212 such that the particles may pass from the passageway 214 withinthe body 212 into the annular cavity 210. The particles may be evacuatedfrom the purge mechanism 224 because the pressure in the annular cavity210 may be lower than the pressure within the passageway 214 of the body212. The pressure differential may be sufficient to urge the particlesout of the purge mechanism 224 and into the annular cavity 210. Theparticles may then flow out of the annular cavity 210 through the secondseal 208, as indicated by the flow arrows. This air may be fed to theforward rim cavity.

FIG. 2B shows a top-down view of the TOBI along the line B-B of FIG. 2A.As shown, the purge mechanism 224 is configured on an outer curve radiusof the body 212. That is, as shown by the arrows, the air flow willtravel toward the right on the page, and then upward. As the air flowmakes the turn within the passageway 214 of the TOBI, particles may havesufficient weight/size combination that they cannot make the turn andmove to the outer curved wall of the body 212 of the TOBI. The particlesmay pass through a purge cavity entry 228 and into a purge cavity 230.The purge cavity entry 228 may be a hole in the wall of the TOBI, andallow fluid communication between the passageway 214 and the purgecavity 230. When the particles are within the purge cavity 230, thepressure differential between the passageway 214 and the annular cavity210 will force the particles to flow into the annular cavity 210.

Referring again to FIG. 2B, after passing the purge mechanism 224, theair flow within the passageway 214 may be further separated by aseparator 232. The separator 232 may be a fin, blade, or other device orstructure that is configured to separate the airflow in the TOBI into afirst flow path 234 and a second flow path 236. The first flow path 234may be adjacent to the outer wall of the body 212 and may follow thepurge mechanism 224 along the flow path. Particles that remain in theairflow after passing the purge mechanism 224 may flow into the firstflow path 234. The air from the first flow path 234 may then flow towardthe turbine 200 around a divider 238 and into portions of the blade 204.This air may be used to cool portions of the blade that have holes andpassages of sufficient size to accommodate some particles.

The air that passes through the second flow path 236 may be the cleanestair, with the largest particles filtered out by the inlet extension 220,the medium particles filtered out by the purge mechanism 224, and thesmall particles filtered out by the separator and the first flow path234. This air may flow on an interior side of the divider 238 and besupplied to the portions of the turbine 200 that have the smallestholes.

In some embodiments, the air that passes through the first flow path 234may be referred to as inboard air and the air that passes through thesecond flow path 236 may be referred to as outboard air. In someembodiments, the separator 232 may be configured to have the first flowpath 234 be angled downward and the second flow path 236 may be angledupward. This is shown, for example, in FIG. 2C, which shows a partialschematic view of the exit end of the TOBI, with two sets of exit pathsfrom two separate passages 214 shown. As depicted, the first flow path234 and the second flow path 236 are physically separated by theseparator 232. Also shown in FIG. 2C is the purge cavity 230 that isconfigured to expunge particles prior to reaching the first flow path234 and the second flow path 236.

Turning now to FIG. 3, a schematic illustration of a gas turbine enginein accordance with another non-limiting embodiment is shown. In FIG. 3,a turbine 300 (partially shown) comprises a disk 302 supporting aplurality of circumferentially spaced blades 304 (one being shown). Afirst seal 306 and a second seal 308 are configured to define an annularcavity 310 just ahead of the turbine 300. A TOBI 312 defines apassageway 314 that is configured to receive compressor discharge airand deliver it to the turbine rotor through a plurality of nozzles.Similar to the embodiment shown and described with respect to FIGS. 2Aand 2B, the TOBI 312 includes an inlet extension 320 with an area 318formed below the inlet extension 320 and configured to collectparticles. The TOBI 312, as shown, also includes a purge mechanism 324and a separator 332.

The primary difference between the configuration of FIG. 3 and thatpreviously described is the airflow as it leaves the TOBI 312. As shown,a first flow path 334 may direct airflow downward after the air leavesthe first flow path 334 of the TOBI 312. The air may flow from the firstflow path 334 downward and around the disk 302 as shown by the flowarrow in FIG. 3. The air may be directed toward the trailing edge of theblade 304 by a deflector 340. The deflector 340 may be a plate or othertype of cover or component.

The air from the second flow path 336 may be similar to that shown anddescribed above. That is, the air from the second flow path 336 may flowtoward the turbine 300 and then into portions of the blade 304 toprovide cooling thereto.

Turning now to FIG. 4, an alternative non-limiting example of the purgecavity configuration is shown. FIG. 4 shows a top-down view of a TOBIhaving an alternatively configured purge mechanism 424 configured on anouter curve radius of the body 412. Similar to that described above, theair flow will travel toward the right on the page, and then upward. Asthe air flow makes the turn within the passageway 414 of the TOBI,particles may have sufficient weight/size combination that they cannotmake the turn and move to the outer curved wall of the body 412 of theTOBI. The particles may pass through a purge cavity entry 428 and into apurge cavity 430. The purge cavity entry 428 may be a hole in the wallof the TOBI, and allow fluid communication between the passageway 414and the purge cavity 430. When the particles are within the purge cavity430, the pressure differential between the passageway 414 and an annularcavity will force the particles to flow into the annular cavity, asdescribed above. In this embodiment, the purge cavity includes aprotrusion 425. The protrusion 425 may be a lip or other extension atthe purge cavity entry 428 that is configured to aid in capturing largeparticles that pass through the passageway 414. Also shown in FIG. 4 isan alternative geometry of the purge cavity 430. In this embodiment, thepurge cavity 430 is squared shape, wherein in FIG. 2B the purge cavity230 has a rounded shape. As will be appreciated by those of skill in theart, the purge cavity may take any desired configuration, shape, orgeometry, without departing from the scope of the present disclosure.

Turning now to FIGS. 5A-5C, alternative non-limiting configurations ofthe inlet extension are shown. In FIG. 5A, the inlet extension 520 a maybe configured to extend 180° from the direction of flow through thepassageway 514 a. That is, an inlet 522 a of the inlet extension 520amay be configured to force air that flows into the passageway 514 a ofthe TOBI to change air flow direction by 180° when flowing into andthrough the TOBI.

In FIG. 5B, the inlet extension 520 b may be configured to extend 270°from the direction of flow through the passageway 514 b. That is, aninlet 522 b of the inlet extension 520 b may be configured to force airthat flows into the passageway 514 b of the TOBI to change air flowdirection by 180° when flowing into and through the TOBI.

In FIG. 5C, the inlet extension 520 c may be configured to extend 90°from the direction of flow through the passageway 514 c. That is, aninlet 522 c of the inlet extension 520 c may be configured to force airthat flows into the passageway 514 c of the TOBI to change air flowdirection by 90° when flowing into and through the TOBI.

As will be appreciated by those of skill in the art, the change in flowdirection and configuration of the inlet extension may be configured atany desired angle. For example, in a single system different inletextensions about the 360° of the TOBI (see, e.g., FIG. 1B) may havedifferent angles and/or configurations, such that particles may beprevented from entering the passageway of the specific portion of theTOBI.

Turning now to FIG. 6, a process flow for manufacturing a gas turbineengine in accordance with an embodiment is shown. Process 600 may beperformed during a manufacturing of a gas turbine engine or may beperformed to retrofit a gas turbine engine with features describedherein. As such, a gas turbine engine, or a portion thereof, may beprovided (block 602). The gas turbine engine may be fitted with an inletextension at the TOBI (block 604). The inlet extension may take the formof any of the above described embodiments or variations thereof. In someembodiments, the fitting of the inlet extension may be to fit a flowpath extension to the inlet of a TOBI such that the extension isdirected in the direction of the flow path of air in the engine and aninlet to the extension is oriented in a direction opposing the airflowso that air flowing into the inlet must change direction when flowinginto the inlet extension. The inlet extension may be configured tofilter or separate particles from entering the inlet of the TOBI andfurther may be configured to prevent particles from falling into theTOBI by the force of gravity.

A purge mechanism may be formed in or on the TOBI (block 606). The purgemechanism may be configured on an outer curve of the TOBI such thatparticles may be captured in a cavity of the purge mechanism and then beevacuated from the purge cavity. Finally, a flow separator may be formedat an exit of the TOBI to separate airflow as it exits the TOBI (block608). The separator may be configured to have particles in the air atthe exit of the TOBI to flow in a different path from air that does notcontain particles.

Those of skill in the art will appreciate that the flow process 600 maybe modified without departing from the scope of the present disclosure.For example, the TOBI may be pre-fabricated with the purge mechanism andthe separator, and then installed into the engine. Furthermore, in someembodiments, the inlet extension may be formed as part of the TOBI andinstalled therewith. In some embodiments, all of the blocks 602-608 maybe performed simultaneously, such as in an additive manufacturingprocess. In some embodiments, the engine may already have a TOBI (withor without the purge mechanism and/or the separator) and the inletextension may be retrofit or installed on the engine. Thus, the processorder of the blocks 602-608 is not limiting.

Turning now to FIG. 7, a process flow of operating a gas turbine engineis shown. Process 700 may be operated with a gas turbine engine having aTOBI configuration with an inlet extension, a purge mechanism, and aseparator at the outlet or exit of the TOBI. The flow process 700 may beviewed as a conveyance of air through a portion of a gas turbine engine.

First, air may be directed to flow in a reverse direction when enteringan inlet extension of the TOBI (block 702). As the air is redirected ina reverse flow, large particles may not be able to enter the TOBI andmay fall and collect below the inlet extension. Next, the air may bepassed into the TOBI and toward a purge mechanism at a curve or turnwithin the TOBI (block 704). As particles in the air attempt to turnwithin the TOBI they will move to the exterior or external radius of thecurve, and may be captured in a purge cavity of the purge mechanism. Theparticles in the purge mechanism may then be forced from the purgecavity. The air may then be separated into first and second flow paths(block 706). For example, a first flow path may be configured in adownward direction, relative to the TOBI, such that particles in the airleaving the TOBI may flow in the first flow path and be directed toparticular portions of a turbine blade (block 708). In some embodimentsthe first flow path may provide air to portions of the blade thatrequire cooling but have holes or pathways that are sufficiently largeto accommodate some particles. The second flow path may be configured todirect air with little to no particles and/or particles that are veryfine to portions of a blade that require cooling have very small holesor pathways (block 708).

Advantageously, embodiments described herein provide mechanisms andprocesses for filtering particles from airflow as it passes through aTOBI prior to being supplied for cooling an airfoil. Further,advantageously, particles of large size may be filtered by an inletextension configuration at the inlet side of a TOBI such that theparticles cannot enter the inlet extension and thus cannot enter theTOBI. Further, advantageously, the configuration of the TOBI inletextension may be such that large particles may collect below and/or awayfrom the inlet of the TOBI such that upon start up, the large particleswill not be forced into the TOBI.

Further, advantageously, embodiments described herein provide a purgingmechanism that is configured to filter particles out of the TOBI as theparticles pass through the TOBI. Advantageously, as the air flows intothe TOBI and around a curve, the particles are forced to the exteriorradius of the curve and may be captured in a purge cavity. The particlesmay then be evacuated from the purge cavity due to a pressuredifferential between air in the TOBI and air in a cavity external to theTOBI.

Moreover, advantageously, embodiments described herein provide an airflow separator at an exit of a TOBI to separate the airflow into twoflow paths. A first flow path may be configured to carry small particlesin the first flow path and then direct the flow to portions of a turbinethat may accommodate small particles in the airflow. A second flow pathmay be provided with low particle content (e.g., small number ofparticles and/or fine particle size) to portions of a turbine that mayrequire cooling but may not be able to accommodate high quantitiesand/or sizes of particles in the cooling air.

While the present disclosure has been described in detail in connectionwith only a limited number of embodiments, it should be readilyunderstood that the present disclosure is not limited to such disclosedembodiments. Rather, the present disclosure can be modified toincorporate any number of variations, alterations, substitutions,combinations, sub-combinations, or equivalent arrangements notheretofore described, but which are commensurate with the scope of thepresent disclosure. Additionally, while various embodiments of thepresent disclosure have been described, it is to be understood thataspects of the present disclosure may include only some of the describedembodiments.

For example, although shown and described with various embodimentshaving an inlet extension, a purge mechanism, and a separator, those ofskill in the art will appreciate that in other embodiment only one ortwo of the features may be provided, without departing from the scope ofthe present disclosure. For example, a gas turbine engine may beconfigured with an inlet extension but may not include a purge mechanismor a separator. Further, although described with respect to turbineblades, those of skill in the art will appreciate that the airflow maybe used to cool vanes or other airfoils.

Accordingly, the present disclosure is not to be seen as limited by theforegoing description, but is only limited by the scope of the appendedclaims.

What is claimed is:
 1. A tangential on-board injector for a gas turbineengine, the tangential on-board injector comprising: a body having anentrance and an exit, the body having a curved shape and defining an airpassageway between the entrance and the exit; and an inlet extensionconnected to the entrance of the body, the inlet extension extendingfrom the body and having an inlet configured to force air to changedirection when entering the inlet of the inlet extension.
 2. Thetangential on-board injector of claim 1, wherein the inlet extension isconfigured to direct air through an angle as the air flows through theinlet extension.
 3. The tangential on-board injector of claim 2, whereinthe angle is equal to or greater than 90°.
 4. The tangential on-boardinjector of claim 1, wherein the inlet extension is integrally formedwith the body.
 5. The tangential on-board injector of claim 1, furthercomprising a purge cavity configured along the air passageway of thebody, the purge cavity configured such that large particles in anairflow through the passageway will enter the purge cavity.
 6. Thetangential on-board injector of claim 5, wherein the purge cavity isconfigured to expel particles from the purge cavity to an annular cavityexternal to the body.
 7. The tangential on-board injector of claim 1,further comprising a separator located at the exit of the body, theseparator configured to separate an airflow flowing through the airpassageway into a first flow path and a second flow path.
 8. Thetangential on-board injector of claim 7, wherein the first flow path isdirected inboard relative to the body and the first flow path isdirected outboard relative to the body.
 9. The tangential on-boardinjector of claim 7, wherein each of the first flow path and the secondflow path are configured to direct air to cool components of a gasturbine engine.
 10. A method of manufacturing a gas turbine enginehaving a tangential on-board injector, the method comprising: installingan inlet extension to an entrance of a body of the tangential on-boardinjector, the inlet extension extending from the entrance and having aninlet configured to force air to change direction when entering theinlet of the inlet extension.
 11. The method of claim 10, wherein theinlet extension is configured to direct air through an angle as the airflows through the inlet extension.
 12. The method of claim 11, whereinthe angle is equal to or greater than 90°.
 13. The method of claim 10,wherein the installation comprises integrally forming the inletextension with the body of the tangential on-board injector.
 14. Themethod of claim 10, further comprising forming a purge cavity configuredalong the body, the purge cavity configured such that large particles inan airflow through the body will enter the purge cavity.
 15. The methodof claim 14, further comprising configuring the purge cavity to expelparticles from the purge cavity to an annular cavity external to thebody.
 16. The method of claim 10, further comprising forming a separatorat an exit of the body, the separator configured to separate an airflowflowing through the body into a first flow path and a second flow path.17. A gas turbine engine comprising: tangential on-board injectorhaving: a body having an entrance and an exit, the body having a curvedshape and defining an air passageway between the entrance and the exit;and an inlet extension connected to the entrance of the body, the inletextension extending from the body and having an inlet configured toforce air to change direction when entering the inlet of the inletextension.
 18. The gas turbine engine of claim 17, wherein the inletextension is configured to direct air through an angle as the air flowsthrough the inlet extension.
 19. The gas turbine engine of claim 17,further comprising a purge cavity configured along the air passageway ofthe body, the purge cavity configured such that large particles in anairflow through the passageway will enter the purge cavity.
 20. The gasturbine engine of claim 17, further comprising a separator located atthe exit of the body, the separator configured to separate an airflowflowing through the air passageway into a first flow path and a secondflow path.